Heat exchangers of the rotary regenerator type



June 30 1959 w. s. Mlsl-:NER

HEAT EXCHANGERS OF THE ROTARY REGENERATOR TYPE Filed June 12, 1953 5 Sheets-Sheet 1 INVENTOR. C/ay J'.

June 30, 1959 w, 5, MlsENER 2,892,615

HEAT EXCHANGERS OF THE ROTARY REGENERATOR TYPE Filed June 12, 1953 5 Sheets-Sheet 2 k ,Y l

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may JM HEAT ExcHANGERs oF THE: ROTARY REGENERATOR TYPE Filed June 12, 1953 l June 30, 1959 w. s. MISENER 5 Sheecs-Sheetv 3 wN NN INVENTOR. /QQZEU J'. MM2/M June 30, 1959 2,892,615

HEAT ExcHANGERs 0F THE: ROTARY REGENERATOR TYPE Filed June 12. 1953 w. s. MlsENER 5 Sheets-Sheet 4 INVENTOR.

am aux June 30, 1959 I w, '5, MlsENr-:R 2,892,615v

HEAT EXCHANGERS OF' THE ROTARY REGENERATOR TYPE Filed June 12. 1953 5 Sheets-Sheet 5 .7 so FIG a y se 6.3 f2 ',2 27 I 4 v es VT 7s JY 65 'br r :SV 7s INVENTOR. Ua-ZZ@ J'. Mm

United States Patent O HEATEXCHANGERS OFTHE ROTARY' REGENERATOR TYPE Walter S. Miseuer, Syracuse, N.Y., assignor to 'Carrier Corporation, Syracuse, NJY., a -corporation of'Dela-` `ware Application June 12, 1953,` Serial No.:361,215

6 Claims. (Cl. 257-6) This invention relates'to regenerators and, more par-v ticularly,'to regenerators in which the heat storage me-l dium'ormatrix rotates about an axi-straversing in turn two "fluid streams flowing through the regenerator. The

tWo streams are at different temperatures and at substantially different pressures. In this type of regenerator, a portion of the matrix passes through the warmgas duct and absorbs heat from the gas therein after which it passes adjacent a sealing means into the cold gas duct where itgives up heat to the gas therein, then passes adjacenta second sealing means or other portion of the rst sealing means back into the warm gas duct to repeat theprocess.

The principal problems connected with this type of regeneratorare those of #leakage through the seal from the high pressure duct to the lowY pressure duct, and of carryover ,of gases trapped within the matrix, thus causinga net loss of gas from the high pressure duct. Loss of gas from thehigh pressure duct is. caused'byboth of these phenomena; when this lossbecomes excessive the value ofthe regenerator as an exchanger is impaired. In fact, to my knowledge, prior to the present invention, no :satisfactory solution for these problems hasbeen Vpresented.

Thepresent invention satisfactorily `solves the problem while-,keeping other losses, Ysuch as pressure drop, within reasonable bounds by removing the seal from-the regenerator matrix and reducing its perimeter totthereby reduce the leakage. Such procedure results` in some additional volume between the seals withiny the rotor ,which isundersirable since it increases the carryover. However, with the present arrangement, thet increase in carryover is less than the decreasein leakage so that an provement in performance is obtained. The geometry for -a minimum total of leakage and carryover maybe. deiinedin -terms of the matrix and seal characteristics..Y

The chief object of this invention isto providea refv generator having a matrix soformedthat thecombined.

total percentage of leakage and carryover is the minimum possiblefor any given set ofmatrixtand seal characteristics.

A further object is to provide a ,stationary seal plate for a regenerator which will continuously seal` against a rotatingseal plate despite a varying pressure loadtending,

to separate these two plates.

Another object is to provide a regenerator in which `the matrix isfOrmed of two, concentric, oppositely tapered, truste-conical members or elements permitting axial flow into the matrix assembly, substatially radial flow through the matrix itself, and axial ow from the matrix assembly;

Other objects of my invention will be readily perceived` from the following description.

`This invention relates to a regenerator comprising van annular housing, the housing having yinner and outer concentric walls, a matrix member disposed in the housing, said member comprising -two .substantially frustoconical. elements extendingin oppositedirections about the axis of the housing, means dividing said elements into ment of my invention, in which:

Figure 1 is an isometric view of the whole matrix;

Figure 2 is a sectional -viewA takenk along the line II-II of Figure 1;

Figure 3 is a diagrammatic view of a portion of the regenerator showing details `of the'flow path;

Figure 4 is a sectional view of one embodiment of the regenerator;

Figure 5 is an end view partly in section and elevation of the regenerator of Figure 4;

Figure V6-is an en'd view partly in-section l and partly, in elevation of the'regenerator taken in the opposite;di' rection of Figure 5;

Figure 7 is a sectional view of a modification ofthe invention;

Partlyia Figure 8 is a sectional viewof the compensating njleans upon the use of two concentricfrusto-conica'l matrices of opposite taper, as shown in Figure l. This arrange` ment enables a relatively large matrix frontal area to be'V disposedV between small ilow entrance -and exit areas, which results in small seal perimeters. The matrix frontal areais the area which is normal tothe flow. ThisA area is the surface area of the facing side of the'two frusto-conical matrix elements. This arrangement, however, leaves space between the sealing-planes Within the rotor, which is not usefully occupied by the matrix whichI contributes to thecarryover. The smaller theseal perimeter, theless will be leakageffor any given quality of seal (leakage per -foot of seal length) andthe larger wifllhe'eV the carryover for varegenerator ofthe preferred arrange-V ment. ThisV situation means that an optimum design'` existsin which for a givenmatrix design requin'ngga; givenfamount ofmatrix frontal area and depth; ofkmatrixf and afgiven seal leakage per footoflength a specific-1v .geometry exists such that the total of leakage andcarry.- v

over-is aiminimum. Figure 3 -shows afcrosssectionof a. portion-ofthe regeneratorrotating housing onwhich the basic dimensionsare-illustratedwhich dene-Awhatqis; referredv to-as the regenerator geometry, andralso what; parameters and assumed dimensions arel required to en?,

ablean optimumdesign -to be obtained.

VHere the-major'passage radius `at the smallenopening;

(Figure 3) must -be such that and the minor` passage radius at the smaller (Figure 3,) must; besuch that in whichu caser thef total-percentage of',` leakage and f carryf over is givennby,

Openia for best perfomance inV which C' (L sin @+A cos 0) cos sin 6 Encarta/Af,

and

Afa is matrix frontal area in high pressure region, ft2.

C4 is the fraction of the total annulus area within the high pressure region of the rotor.

C4 is the fraction of the total annuzlus area within the high pressure ducting approaching the rotor.

k1 is mean leak rate of circumferential portion of the seal, lbs./sec. ft.

k2 is mean leak rate of the radial portion of the seal,

lbs/see. ft.

l is axial length of regenerator matrix, ft.

L is additional axial length of rotor inside seals, usually equal to matrix thickness, ft.

N is rotor revolutions per minute.

Wa is weight ow through high pressure region, lbs/sec.

0 is half cone angle of matrix, degrees.

p is mean density difference (high pressure region minus low pressure region), lbs./ft.3.

A is distance from passage to inner and outer walls of rotor annulus.

It will be understood that the matrix, as previously described, must be incorporated within a housing and between sealing plates in order to serve its function as a heat transfer member. Means must also be provided for supplying gases of different temperatures to portions of the matrix members at different times. While the desired type of matrix member is that shown in Figure 1, it is desirable for commercial manufacture that these members 2 and 3 be divided into a plurality of portions circumferentially displaced from one another in order to limit the amount of carryover and assure effective heat transfer.

The particular type of regenerator, which I have found preferable, is shown in the drawings. Referring particu- `larly to Figure 4, there is shown a casing 4. An annular housing 5 is located within the casing and spaced therefrom. This housing is adapted to be rotated and its particular operation will be described hereinafter. The housing is divided into a plurality of trapezoidal chambers 9. These chambers are provided by forming the housing of a series of separate boxes 6, which are trapezoidal in cross section. Each box contains a chamber 9. The details of the boxes will be described hereinafter.

It is obvious that the division of the housing into a plurality of chambers necessitates the division of the two matrix members 2 and 3 into a plurality of portions circumferentially displaced from one another. Each portion of the matrix member 2 isk identified by the reference numeral 12, while each portion of the matrix member 3 is identified by the numeral 14. Each chamber 9 will contain a portion 12 and a portion 14, thus the portions 12 will make up the frusto-conical member 2, and the portions 14 will make up the frusto-conical member 3. The basic arrangement shown here, and in Figure l, in which the matrix is arranged in the form of two frustoconical members permits a very large matrix frontal area or surface to be provided in a relatively small space. This permits the flow to be essentially radial through each portion 12 of member 2 and'each portion 14 of member 3 and results in low pressure losses. The arrangement also permits the flow to be essentially axial into and out of the matrix assembly so that a seal of small perimeter may be used.

Attached to each end of the annular housing 5 is a seal plate 15, which is adapted to rotate with the housing. Each of these rotating seal plates has openings 16 that communicate with the chambers 9. These openings are of smaller size than the chambers to permit the mounting of the ends of the boxes 6 in the housing 5. If desired, one of the rotating seal plates may have openings of the same size as the chamber.

The manner in which the regenerator may be formed is disclosed in the copending application of P. A. Weller, Serial No. 361,278, tiled June 12, 1953. In the preferred method of assembly, a series of discrete boxes 6 are formed, each box containing a chamber 9. These box, which are trapezoidal in cross section, t into grooves 17 formed in rotary seal plates 15. These grooves, of course, are of trapezoidal form. The seal plates 15 are held together against the boxes by a tie rod 18 and turnbuekle 19. While this method of assembly is preferred, it will be understood that other suitable means of assembly may be employed.

A stationary seal plate 22 is positioned adjacent one of the rotating seal plates. This stationary seal plate is preferably circular to surround both the high pressure and low pressure passages with radial seals between the two, but it may be a sector of a circle and surround only the high pressure passage. This stationary seal plate 22 is afxed by means of a bellows 25 to the stationary structure or casing 4 which is connected to ducts 23 and 24. Bellows 25 permits the stationary seal plate 22 to move with respect to the housing 5 and the casing 4.

At the other end of the housing there is located a second stationary seal plate 26. If desired, this plate may be circular, but it preferably is only a sector of a circle surrounding high pressure duct 27 for a reason to be described hereinafter. This plate 26 is aiiixed to the casing 4 by a bellows 29 and hence it is fastened to the duct 27 since the duct is connected to the casing 4. Thus, this stationary seal plate 26 is capable of moving with respect to the housing 5 and the casing 4.

High pressure gas flows from duct 27 to the housing, then flowing through the seal into the group of chambers 9, which happen to be opposite the high pressure duct at that time, and out through the seal to duct 23. The low pressure gas flows from duct 24 to the housing, then passing through the applicable chambers 9 and leaves the housing, passing to the duct 2.8. While the flow of high pressure and low pressure gases is shown to be in opposite directions and such an arrangement is preferred, it will be understood that the llow of gases could be in the same direction.

Since it does not matter if the low pressure gas leaks from the duct into the space between the housing and the casing provided, of course, that it does not bypass the housing, only the high pressure passage need be sealed on either end of the regenerator. Means must be provided, however, to prevent the low pressure gas stream from bypassing the housing. This is accomplished, of course, when the stationary seal plate 22 is a complete circle. If the plate 22 is only a sector of a circle surrounding the high pressure passage, a seal must be provided at the inner and outer radii of one of the rotating seal plates 15.

Gear teeth 32 are shown on the periphery of the seal plate 15. These teeth mesh with gear teeth 33 of drive gear 34. This drive gear is connected by a shaft to a motor 35. While the housing is described as being rotated by rim drive, a shaft drive may be employed if desired. It also will be understood that suitable means .may-be.pr0vided{torotatehedusts iff-desirsdfths-hous- The stationary seal plates are composed offradial-,por-

.tions 40, i sa inner .fconssntrie ,portion '41, fand. an opter .gonsentric .Portion s42- =.T,h.e .area .inside ...these portions i portions assume theshape of-completelypircular members instead of .segmentspfaircle and it is preferable to join the inner and outer CQnCentric portions by a small additional radial portionspanning what now becomes the low pressure passage.

:Itis obvious that as each chambercontaining high pressure gas passes under one of the radial portions- Qta stationary seal plate that this particular radial portion will be subjected to avarying pressure, which will tend to lift the stationary plate away from the rotating plate and permit high pressure gases to leak into the low pressure sector. ATherotatio'n of-the rotary'seal plate with the housing causes the position of the actual line of sealing to move across the radial1portion of the stationary seal plate, exposing varying parts of this portion to high and low pressures thereby causing avariable lifting force.

To assure sealing, it isdesirable to apply a compensating force that is constant and4 equal to the maximum Value of the lifting force or acmpensating force that varies with the lifting force. I have found a practical solution using a compensating force that varies step-wise with the lifting force.

Each of theradialportions ofthe sealing plates is provided with .a pluralityof ..holes50.that arefspaced from one another. -These holes are illustrated (see Figure as being inclined with respect to each other, but they may be placed on the same circumference Preferably, each of these holes (see Figure 8) is connected directly to a compensating bellows V 44, which is connected to the sealing plate. This vbellows is -located in a cover 45 fastened to the casing 4. Disposed between the bellows and the cover is a ram .46. As the first pressure hole is exposed to the high Lpressure region, the compensating bellows connected to-thisihole picks up the same pressure. This results in the bellows attempting to expand towards the cover 45 but the ram 46 prevents this and the bellows expands towards the sealing plate. This causes the sealing plate to remain `in .the-desired sealing yposition adjacent the rotary plate. As -the second vhole is exposed the second 4bellows takes elect. It is obvious that the number of `bellows that can vbe used willrdepend on the particular desired results.

In the embodiment of Figure 9, thecompensating bellows -44 is directly.connected-to'the.hole.50 andthe sealingplateas inlFigureS. Ontheend of'the'bellows44, there is provided a member 47on which arehinged, at 47', two levers 48. Portions 4S of-these levers extend therefrom to act Aon `the sealingrplate. Each of these levers 48 has a fulcrum, ywhich is provided by `the bolts 49 lin the cover .45. These bolts are adjustable to prevent the bellows from being-extended lbeyondfthe desired limit Aand to assure that the lportions -48 -will contact the seal plate when any pressure is applied through the hole 50 to bellows 44. As the hole 50 is exposed to the high Pressure .regiomtm compnsatinstbsllows `picks up this pressure. This results in the bellows attempting to expand but its traizelsisdimited. However, .it does move sutiiciently to cause the portions 48 to exert a force on the seal plate. Likewise, dueto thelirnited travel of the b ellows, there Yis va force rkexerted on the plate vby the bellows. Byapplying theforce at threel points rather than one, it is obvious that Ithe size of the bellows may be reduced accordingly. It will be understood that a plurality of these bellows will be connected to a plurality of .holes asin Figure 8.

In the modification of Figure 10, each of the holes 50 is connected through .a .connecting tube 51 -yto the comgpensatingt bellowsfSz. I bellows. is; located; in .-a. cover T-53 fastened tothe casing 4 and pushes againstftheseal by .means of 3a ram 55. As the ,'irst Apressure .hole iis exposed tothehgh pressure region,;the compensating .f bellows connected t o thisfhole/ picks up the same, pressure and-the ram Y55 vcauses thesealing plate to be-pushed z tgainst-the rotating plate withan increased force. As

the second1hole is exposed lthe second ram is actuated. It is obvious that the number of bellows that can Yhe vused will dependon theparticular desired results.

Consideringthe operation of the device, hightempera- `turegasesiiow into the housing through the Vlowpressure `.inlet duct r24. The portions 12 and 14 of the Amatrix members f2 :and 3 absorb -heat from this high tempera- .ture gas and store it vtherein until `they -pass :through the low temperature gas being supplied by the high v:pressure duct 27. .The yhightemperature gases, thaving been'ooled bypassingnthrough the matrix, leave b-y .-ductz. .The.lowtsmperaturetsas enteriugthroughinlet duct 27 absorbs heatfrom the portion 12- and portion 14 of the matrix members 2 and 3 when they arrive opposite ,the highgpressure-strearn. The movement pf the portions .ofthematrixfromone-sectorto another is accomplished .byrotationof the housing 5 by the motor 35 through thedrive gear 34.

It will be-understood that the radial portions of the stationary seal plates `have a greater circumferential Width than any of the openings 16 in the rotary seal plate. This will prevent leakage from the -high pressure side tothe low pressure side. Carryoveris, of course,fdeter mined by the Volume of the chambers v9 and the 'speed of rotation.

Referringsto vthe modification disclosed j in Figure :7, there` is showna casing-60, preferablymade ofaluminum, andan annularhousing 61 disposed withinthe casing 6 0 andspaced therefrom. This .housing 61 is made vup-.of a gplurality Vof `boxes v62 .in the same manner as the housingS .of :Figure v.4. Each of the boxes-62 contains a chamber .63 vin which are-disposed matrix portions 1 2 and 14 inthe same manner as described with regard to `Figure 4.

Attached to eachend of the annular housing is a seal. plate 64 that ,is adapted -to rotate 'with the housing. Disposed between each seal plate and the end of 1the housing isa temperature equalizer member 65 made of copper or other material of high thermal conductivity. Stationary sealplate 67, connected by bellows 66 to the casing.60, `is disposed adjacent one of the rotating seal plates. The second stationary seal plate 6S,.connect e d by v bellows .69 to the casing y60, is disposed adjacent theother rotating seal plate. -Each of these seal plates 67 and 68 forms .only a sector of a circle to provide sealing about the high pressure sector in the samemanner that sealing is accomplished yby the seal plate 26 inthe embodiment of Figure V4. Between the stationary Aplate 67 .and the bellows 6 6 there is disposed a temperature equalizer member 70 kmade of copper or other material of .high'thermal conductivity. The member 70 forms only a sector ofthe circle. A member 71, similar to member 70, is disposed between the stationary seal plate 68 and bellows 69.

.In the sector of the regenerator through which the low pressure gases pass there -is disposed adjacent to eachirotating seal-plate a temperature equalizer member 72 zmade of copper or other -high conductivity material. It .will lbe understood that these members 72 are only asector of a'circle embracing that sector of the regenerator through which the rlow pressure gases pass.

Vanes '74 are disposed adjacent to the portions .12 and 14 of the matrix members 2 and 3. These vanes serve -the lpurpose of guiding the gases radially through theportions 12 and '14. A divider 75 is disposedbetween thefportions 12 and 14 to insure that the ilow entering and leaving vthe chamber 163 is axial.

1`o;in surelthat;the.flow pressure gases will flow through.

7 the chambers 63 and the matrix portion 12 and 14 rather than passing by means of the space between the members 72 and the rotary seal plate 64 through the space between the housing 61 and the casing 60, there is disposed a stationary sealing disk 76 adjacent to the inner edge of the rotating seal plate 64. A similar sealing disk 77 is disposed about the outer edge of the rotating seal plate 64. In the embodiment disclosed in Figure 7 the manner of ow and the heat transfer relation is the same as the embodiment of Figure 4 and an explanation of the operation of Figure 7 is not deemed necessary.

The present invention has the advantage of providing a regenerator with total leakage and carryover at a minimum even though the uid pressures differ greatly. This particular minimum is obtained by a specilic geometric pattern of the regenerator.

While I have described a preferred embodiment of my invention, it will be understood that my invention is not limited thereto since it may be otherwise embodied Within the scope of the following claims.

I claim:

1. A regenerator comprising an annular housing, the housing having inner and outer concentric walls, a matrix member disposed in the housing, said member comprising two substantially frusta-conical elements extending in opposite directions about the axis of the housing, means dividing said elements into separate portions, means for passing high pressure gases in contact with the matrix portions for a predetermined period and for passing low pressure gases in contact therewith for another period.

2. A regenerator including an annular housing divided into a plurality of chambers, a matrix member disposed in the housing, said member comprising two substantially frusto-conical elements extending in opposite directions about the axis of the housing, portions of each element being placed in each chamber, means for passing high pressure gases in contact with each matrix portion for a predetermined period and for passing low pressure gases in contact therewith for another period.

3. A regenerator including an annular housing divided into a plurality of chambers, a matrix member disposed in the housing, said member comprising two substantially frusto-conical elements extending in opposite directions about the axis of the housing, portions of each element being placed in each chamber, and means automatically controlling the passage of both high pressure gases and low pressure gases to and from said chambers at regular time intervals.

4. A regenerator comprising an annular rotatable housing, said housing being divided into a plurality of chambers, a matrix member disposed in the housing about the axis of rotation, said member comprising two substantially frusto-conical elements extending in opposite directions about the axis of rotation, portions of each element being placed in each chamber, means in said housing to permit the ow of hot gases through one passage in communication with the matrix portions and to permit the ow of cool gases through another passage in communication with the matrix portions, the matrix portions absorbing heat during their communication with the hot gases and transferring this stored heat during their communication with the cool gases.

5. A regenerator comprising an annular housing, a matrix member disposed in the housing, said member comprising two substantially frusto-conical elements, said elements being inclined in opposite directions, one of said elements being disposed inside the other, said elements being coaxial with the axis of the housing, means dividing said elements into separate portions along substantially radial planes, means for passing high pressure gases through the annular housing and through the matrix portions therein, means for passing low pressure gases through the housing and through the matrix portions therein, and means for rotating the housing and the matrix therein to permit the various portions of the matrix to pass in turn through the high pressure and low pressure gases.

6. A regenerator including an annular housing divided into a plurality of chambers, a matrix member disposed in the housing, said member comprising two substantially frusto-conical elements extending in opposite directions about the axis of the housing, portions of each element being placed in each chamber, the maximum inner radius of the outer truste-conical element being equal to Wax-i-E/x 2 the minimum outer radius of lthe inner truste-conical element being equal to Wax-E/x 2 and the length of each of the elements being equal to where the magnitude of x is such that for best performance in which 5p'N sin 0 cos 8 l 400k; sin 0 and Afa is matrix frontal area in high pressure region, ft?.

C4 is the fraction of the total annulus area within the high pressure region of the rotor.

C4' is the fraction of the total `annulus area within the high pressure ducting approaching the rotor.

k1 is mean leak rate of circumferential portion of the seal, lbs/sec. ft.

k2 is mean leak rate of radial portion of seal, lbs./sec. ft.

L is additional axial length of rotor inside seals, usually equal to matrix thickness, ft.

N is rotor revolutions per minute.

W., is weight ow through high pressure region, lbs/sec.

0 is half cone angle of matrix, degrees.

p is mean density difference (high pressure region minus low pressure region), lbs./ft.3.

A is distance from passage to inner and outer wall of rotor annulus.

References Cited in the le of this patent UNITED STATES PATENTS 2,014,298 Schneible Sept. 10, 1935 2,471,995 Yerrick et al May 31, 1949 2,473,710 Jillson June 21, 1949 2,517,470 Erisman Aug. 1, 1950 2,579,211 Stevens et al 2---- Dec. 18, 1951 2,622,850 Tipler Dec. 23, 1952 2,631,870 Hodson Mar. 17, 1953 2,632,658 Mertz Mar. 24, 1953 (Other references on following page) 9 UNITED STATES PATENTS Stevens et a1. May 11, 1954 Cox et al. May 29, 1956 Williams Aug. 7, 1956 Jendrassik Sept. 6, 1956 5 Jendrassik Jan. 29, 1957 FOREIGN PATENTS Great Britain Feb. 20, 1952 Great Britain Ian. 7, 1953 France July 8, 1929 France Mar. 1, 1950 Belgium May 31, 1952 

